1. Field of the Invention
The present invention relates to a method of forming a field oxide film in a semiconductor device, and more particularly, to a method of forming a field oxide film in a semiconductor device which can minimize an occurrence of a bird's beak by forming a pad polysilicon film between a nitride film and a pad oxide film, defining field regions by patterning the nitride film, and forming an oxidization prevention layer by implanting nitrogen atoms into portions where the bird's beak will occur.
2. Information Disclosure Statement
In general, a field oxide film is formed to isolate semiconductor elements.
FIG. 1 is a sectional view of a semiconductor device for explaining a method of forming a field oxide film according to the prior art. Referring to FIG. 1, a field oxide film 5 is formed by patterning a nitride film 3 and the pad oxide film 2 to define a field region after forming a pad oxide film 2 and a nitride film 3 on a silicon substrate 1, and by forming a channel stop region 4 on the silicon substrate 1 by an ion implantation process.
As a bird's beak B is formed from an edge of the field oxide film 5 to an active region at the time of forming the field oxide film 5, the active region is reduced, causing a great obstacle in the manufacturing of a highly integrated device.